The present invention relates to a method and apparatus for creating a symbolic display, such as a digital display, which is visually perceptable to observers both during the day and at night. Accordingly, this method and apparatus is particularly useful for creating symbols, such as digits, which are formed out of an array of symbol segments so that selected segments will form different selected symbols and which may be remotely controlled by a user to quickly and easily display a desired symbol. Thus, the present invention is adaptable for large format displays such as those used as information or advertising signs.
Remotely controlled display panels have been known for sometime and have been used to display various visual symbols such as numerals and letters. Prior art devices have utilized matrix arrays of lights to display symbols formed by activating a desired pattern of lights. Other known devices utilize a matrix array of discs wherein one surface of the disc is colored to match a background while the opposite surface is colored with a contrasting material. The symbol pattern is defined by manipulating the discs to presenta desired pattern of contrasting surfaces. Other prior art devices have used shutters for selectively masking symbol segments so that the pattern of segments creates the desired symbol.
A specific example of an electromechanical display assembly is shown in U.S. Pat. No. 4,040,193 issued Aug. 9, 1977 to Matsuda, et al wherein a matrix array of display windows are selectively exposed or masked by means of a plurality of rotatable spheres. A portion of each of these spheres is painted a color that matches the background while the remaining portion of this sphere is painted a contrasting color. An electromagnet controllably rotates selected spheres to generate the symbol pattern.
U.S. Pat. No. 4,070,668 issued Jan. 24, 1978 to Kawaharada, et al discloses a digital display wherein segment windows are selectively masked by means of a pivotal panel which is moved into and out of a masking orientation to a display segment window by means of an electromechanical activating system.
Other types of devices utilize the concept of selectively masking a segment window so that the exposed segments define the selected digit while the masked segments are not visually perceptable. U.S. Pat. No. 4,164,824 issued Aug. 21, 1979 to Nidelkoff shows a seven segment digit display wherein the window shutter elements are operated manually by sliding the shutter panel into a position masking segment window to mask that segment window. U.S. Pat. No. 4,063,377 issued Dec. 20, 1977 to Hukill discloses a changeable display device which is manually operated from a remote location by means of a plurality of cables which are connected to shutter element which define the displayed symbol.
Despite the panoply of display systems which have been developed in the past, there is still a need for a reliable display device which is simple in construction yet which can reliably reproduce a selected range of symbols on command from a remote location. There is a further need for a rugged, outdoor display device that can be visually perceived by an observer both during the day and at night.